1. Field of the Invention
This invention relates to an expansion joint for a cable tray apparatus for use with a people mover system such as a Sky Train or the like. Even more particularly, this invention relates to an expansion joint which is positioned between a pair of cable trays with the expansion joint being selectively laterally horizontally adjustable with respect to the adjacent cable trays and selectively vertically adjustable with respect to the adjacent cable trays.
2. Description of the Related Art
In people mover systems such as a Sky Train system, a plurality of vehicles or cars travel along a guideway or roadway with the guideway or roadway being normally elevated. Power and control signals for the cars normally comprise cables positioned in trays which are positioned on the roadway on one side of the cars traveling on the roadway. Prior to the invention of the co-pending application, it is believed that the cable trays had to be cut and welded together to accommodate curves in the roadway and to accommodate elevational changes in the roadway.
The cable trays of the co-pending application were designed to be secured to one another in an end-to-end relationship with the cable trays being selectively laterally horizontally adjustable with respect to one another and being selectively vertically adjustable with respect to one another to correspond to curves in the roadway and to correspond to elevational changes in the roadway respectively.
It has been found that it is necessary to provide expansion joints or expansion joint cable trays at spaced locations along the cable tray system to compensate for temperature changes. For example, in Phoenix, Ariz., the cable tray system could be subjected to very high daytime temperatures and quite low night time temperatures. Expansion and contraction of the cable tray system may cause damage to the cable trays in the system.